2907121981 has 2 divisors, whose sum is σ = 2907121982. Its totient is φ = 2907121980.

The previous prime is 2907121967. The next prime is 2907122003. The reversal of 2907121981 is 1891217092.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1570853956 + 1336268025 = 39634^2 + 36555^2 .

It is a cyclic number.

It is not a de Polignac number, because 2907121981 - 2¹⁹ = 2906597693 is a prime.

It is a super-2 number, since 2×2907121981² = 16902716424826728722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2907121951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1453560990 + 1453560991.

It is an arithmetic number, because the mean of its divisors is an integer number (1453560991).

Almost surely, 2^2907121981 is an apocalyptic number.

It is an amenable number.

2907121981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2907121981 is an equidigital number, since it uses as much as digits as its factorization.

2907121981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 40.

The square root of 2907121981 is about 53917.7334557008. The cubic root of 2907121981 is about 1427.2095781111.

The spelling of 2907121981 in words is "two billion, nine hundred seven million, one hundred twenty-one thousand, nine hundred eighty-one".